Index-head.



No. 798,970. PATENTBD SEPT. 5, 1905. H. R. MOGREGOR.

INDEX HEAD.

APPLICATION FILED PEB.5,1904.

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mliw a slum! cm nmwuvuuclmacm. mmuumm u c No. 798,970. PATENTED SEPT. 5,1905. H. R. McGREGOR.

INDEX HEAD.

APPLICATION FILED F315. 1904.

2 SHEETS-SHEET 2.

WITNESSES vz/v 7-0;?

mcazwv I cnmul om mmwaumns. wnmnam 0 a UNITED ST ATES PATENT onFIoE.

HUGH R. MGGREGOR, OF PROVIDENCE, ItIIODIC ISLAND, ASSIGNOR TO BROIVN ANDSHARPE h'IANUFAC RING COMPANY, OF PROVIDEI'CE, RHODE ISLAND, ACORPORATION OF RHODE ISLAND.

INDEX-HEAD.

Specification of Letters Patent.

Patented Sept. 5, 1 905.

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Be it known that I, HUGH R. MGGREGOR, of the city and county ofProvidence and State of Rhode Island, have invented certain new anduseful Improvements in Index-Heads; and I do hereby declare thefollowing specification, taken in connection with the accompanyingdrawings, forming a part of the same, to be a full, clear, and exactdescription thereof.

The invention relates to index-heads such as are used, for instance, inmilling-machines for supporting and spacing the work. These index-headsas commonly constructed are provided with an index-plate havingcircularlyarranged series of index-holes and with an index-pin carriedin an arm connected, through suitable gearing, with the spindle of thehead. During the, cutting operation the index-pin is in engagement withone of the holes in the index-plate, and the work is therefore held in adefinite relation to the index-plate. In spacing or indexing the workthe index-pin is withdrawn from a hole in the index-plate and the armcarrying the pin is rotated through the distance required to give thedesired spacing of the work and the pin then inserted either in the samehole or in a ditferent hole in the index-plate. In order to quicklydetermine the proper hole into which the index-pin should be inserted incase the spacing does not require a given number of complete turns ofthearm carryingtheindex-pin,theindex-heads are provided withsector-arms. which may be set to embrace any desired number of holes onthe index-plate. In setting these arms it has heretofore been necessaryto count the number of holes which should be embraced between the armsfor any given spacing, this number being taken from the index-tableshowing the proper number of turns to be given to the index-pin arm andthe number of holes which should be embraced between the sector-arms togive the proper settin for any given spacing of the work. This manner ofsetting the sector-arms requires time and extreme care on the part ofthe operator, who almost invariably counts the holes to be embracedbetween the sector-arms a number of times to make sure that the settingis correct. This manner of setting the sector-arms also results infrequent errors in the setting by careless workmen or thoseinexperienced in the use of the indexheads.

In practicing the present invention the opportunity for mistakes insetting the sectorarms is reduced to a minimum, and provision is madefor the accurate and rapid setting of the sector-arms by providing aseries of graduations on the sector-ring, by the use of which thenecessity for counting the holes is eliminated.

The invention will be more fully explained in connection with thefollowing detailed description of a well-known form of index-headprovided with the invention.

In the accompanying drawings, in which this index-head is illustrated,Figure 1 is a vertical sectional view of so much of an index-head as isnecessary to show the application of the present invention thereto; andFig. 2 is a front elevation of the index-plate and sector-arms, theindex-pin arm being indicated in dotted lines.

In the construction shown in the drawings, A indicates the spindle ofthe index-head, which is provided with a worm-wheel A, engaged by a wormA on the index-shaft A. The index-pin arm B is secured in the outer endof the index-shaft A and carries the index-pin B, which is forcedyicldingly forward by a spring (not shown) in the usual manner. Theindex-plate O is secured to a sleeve O, surrounding the index-shaft Aand mounted on a bearing C" projecting from the frame I) of theindex-head. The sleeve O is provided with a gear O, which may beconnected by a train of gearing with the feedscrew of the work-table onwhich the indexhead is mounted in making spiral cuts. \Vhen using theindex-head for making straight cuts, the index-plate C may be held infixed position by a stop-pin E, carried on a sleeve E and arranged to beengaged with one of the holes in the index-plate. This stop-pin may alsobe engaged with the index-plate to hold it in fixed position during theindexing in case the head is being used in making spiral cuts. Theindex-plate is provided with the usual circularly-arranged series ofindex-holes c, the holes in each series being equally spaced and thenumber of holes varying in the different series. The index-plate issecured to the sleeve O by a screw (3' to enable different index-platesto be employed. The index-pin arm B is radially adjustable of the shaftA,

so that the index-pin may be brought into position to register with theholes in any one of the series in the index-plate. The sectorarms F Fproject from the sector-rings F 1 'I divide the circle into anyconvenient number which are mounted on the end of the sleeve C in frontof the index-plate and are held frictionally in position by afriction-plate F3 The sector-ring F is provided with an annular groovein its outer face, in which the sector-ring F is mounted, and theserings are clamped together after being relatively adjusted by means of aclamping-screw F.

As thus far described the construction corresponds to the constructionof index-heads Which have been heretofore in use and is shown merely forthe purpose of illustrating one form of index-head in which theinvention may be embodied.

Heretofore in the use of index-heads such as above described, in whichsector-arms, such as arms F F, have been employed for determining theproper hole into which to insert the index-pin at the completion of theindexing, it has been necessary to count the number of holes embracedbetween the arms in setting the sector-arms. Suppose, for instance, thatthe operator on looking at the index-table finds that the number ofturns to be given to the index-arm B for the required spacing is twentyforty-sevenths of a turn or a certain number of complete turns andtwenty forty-sevenths of a turn. In such case he so adjusts the arm Bthat the pin B will register with the series of holes in the index-platewhich contains forty-seven holes and inserts the pin B in ahole, as c,in such series. The arms F F are then adjusted so that there will betwenty spaces between them when arm F is against the pin B. This is doneby bringing the arm F against the pin B. counting twenty holes,beginning with hole 0 and then adjusting arm F so that the twentiethhole 0 is the last hole uncovered between the arms. The arms are thenclamped in this relative position by tightening the screw F Now when thework is to be indexed the pin B is withdrawn from the hole 0 and the armB turned until the pin registers with the hole 0 in case the spacingrequires twenty fortysevenths of a turn. If the spacing requires anumber of complete turns and twenty fortysevenths of a turn, theoperator gives the arm the required number of complete turns and theninserts the pin B in the hole 0 W'heu the work is to be again indexed,the sectorarms are swung around until the arm F again engages the pin Band the above operation is repeated.

In practicing the present invention means are provided for indicatingthe proper adjustment of the sector-arms for any given spacing of thework without the necessity of counting the holes in the index-platewhich are to be embraced between the sector-arms. This means consists ofa series of graduations f on the sector-ring F and a cooperating mark fon the sector-ring F". The graduation of the sector is purely arbitraryand may of parts. These graduationsshould, however, be separated byangular distances less than the angular distance between adjacent holesin any series of holes in the various indexplates to be used it thegraduations are to enable the sector-arms to be set for any and everyspacing of the work. The location of the cooperating mark on theungraduated sector-ring is also purely arbitrary. In the constructionshown the graduations on the sector-ring are so spaced that they woulddivide the circle into two hundred equal parts. These graduations arenumbered, and the indextable is provided with a column indicating theproper setting of the sector-arms for any given spacing of the work. Toillustrate, su ppose' the worm-wheel A and the worm A are soproportioned that one turn of the arm B turns the spindle A throughone-fortieth of a revolutionthat is to say, suppose the wormwheel andworm are in the ratio of forty to one and suppose it is desired todivide the work into ninety four divisions. In such case in order to setthe sector-arms properly for a spacing which will provide for ninetyfourequally-spaced cuts upon the work the operator finds upon looking at theindex-table that the proper index-circle to be used is the onecontaining forty-seven holes and that the sector-arms should be set withthe Zero-mark f upon the graduation 83 of the graduated sector-ring.This is the setting corresponding to that shown in Fig. 2, in whichthere are twenty-one holes in the index-circle having forty-seven holesembraced between the sector-arms. The operator, however, reads thenumber of graduations corresponding to this setting directly from theindex-table and sets the sector-arms without the necessity of countingthe number of holes. The setting of the sector-arms can therefore beeasily and quickly made and with less opportunity for error than when itis necessary to count the number of holes to be included between the twoarms of the sector.

What I claim, and desire to secure by Letters Patent. is-

An index-head having in combination a spindle,an indeX-pin,anindex-plate provided with several series of circularly-arranged holesfor cooperating with said pin, one of said parts being connected withthe spindle to turn the same, sector-rings carrying sector-arms, aseries of graduations on one sector-ring separated by angular distancesnot greater than the angular distance between adjacent holes in theniost closely arranged series in the index-plate, and a cooperating markon the other sector-ring, substantially as described.

HUGH R. MOGREGOR.

Witnesses:

W. H. THURSTON, J. H. THURSTON.

